The Reapers, also known as the Old Machines by the Geth, are an ancient race of gigantic living spaceships and the main antagonists of the Mass Effect trilogy. Initially thought to be a myth by most of the characters, the Reapers hibernate in "Dark Space" for thousands of years and then return to the galaxy every few millennia to destroy all the Milky Way's most advanced civilizations, most notably the "Protheans", who gave them the name "Reaper". Their motives for doing this are completely unknown, and they claim that it is beyond mortal understanding. The origin of the Reapers is a mystery too, and it is said that they have existed since the beginning of time.